I got all my clutch plates replaced on my silverado. It seems to me that I am driving 60 mph and the speed needle says 45. It is acting like it does not go into the last gear. Also I cut the cruze control on at 40 and it acts crazy giving gas and releasing the gas. I am going to take it back to the shop but I would like to know what it might be before I do so I can understand what is going on. What do you think?

You don’t mention if this is a automatic or a manual transmission. However, your mention of clutch plates indicates it might be an automatic. Also you don’t mention the year of the truck. This putative 1995 4L60E 4 speed automatic transmission might have a sensor problem or a slipping lockup torque converter. Unless you want to check out all the sensors and their associated wiring, having a transmission technician scan the PCM for codes might be the way to go. If you scan the codes yourself post them back and we can help you diagnosis this. In fact, if you repost mentioning “Silverado automatic transmission problem”, ‘transman618’ will probably pipe in with the definitive answer.